Toward More Energy Efficient VLC Networks: A Study on Space Division Multiplexing and Smart Lighting

This paper addresses the challenge of enhancing energy efficiency in Visible Light Communication (VLC) networks through Space Division Multiplexing (SDM) and smart lighting integration. We mathematically formulate the problem of energy-efficient multi-user VLC networking with SDM and smart illumination, tailoring the light output according to the users' demands. To address the arising intricate optimization problem, we propose Clustered Light Emitting Diode (LED) Assignment and Power optimization (CLAP). This heuristic approach leverages density-based spatial clustering for efficient user grouping and employs a greedy sequential algorithm for LED assignment. The constrained optimization by linear approximation technique is employed to determine transmitted optical power levels. By incorporating density functions of achievable rates into precise transmitter models, our study accurately assesses power consumption in VLC system optimization, significantly enhancing energy efficiency. A comparative analysis of three popular VLC network transmitters shows that precise power consumption determination is superior to using common approximations. The proposed methodology showcases remarkable improvements, achieving up to a 55% increase in energy efficiency and up to a 58% reduction in power consumption for a VLC network, with best results observed when utilizing bias-T transmitters, which can accommodate DC biasing, equipped with class AB amplifiers, known for their efficiency.